Skin metastases from head and neck squamous cell carcinoma: Incidence and impact

BACKGROUND: Squamous cell carcinoma (SCC) of the upper aerodigestive tract rarely metastasizes to the skin. This study was designed to review the incidence of skin metastases, to identify associated risk factors, and to investigate the prognostic significance of skin metastases. METHODS: A cohort of 2491 patients treated for SCC originating in the upper aerodigestive tract were evaluated retrospectively. Patients who developed skin metastases were evaluated with respect to tumor stage, treatment, and outcome. Patients with skin metastases were compared with patients who developed distant metastases at other sites and with those who did not develop distant metastases. RESULTS: Skin metastases developed in 19 (0.763%) patients. The median time to occurrence was 6 months. Ninety percent of patients died of disease within a median of 3 months (1 to 16 months) following diagnosis. The development of skin metastasis is most closely related to the presence of two or more cervical metastases and/or extracapsular spread of tumor in the cervical metastases. Similar risk factors were identified for the development of distant metastases to other sites. CONCLUSION: Metastasis to skin is a rare occurrence which has prognostic significance similar to distant metastasis to other areas.